stops responding when saving?

Hi,

I just downloaded the free version, followed all the prompted installation procedures and registered properly. 

computer is a Surface Pro 4.

Program works fine, until i try to save and I lose everything. I can re open, draw, do everything. Until I try save. 

If I try to do a recovery, it does the same thing. 

 

It will let me open previously saved files (loaded via usb stick, or from a received email)

 

any ideas? thanks

Just to add, I had no issues on my previous computer which was a surface 3 with the same OS